D2 Tool Steel (semi-stainless / carbon steel):   D2  is a wear resistant steel used for various cutting tools such a shears and planers. It was first developed around the time of World War II It contains 1.5% carbon and 11.0 – 12.0% chromium; additionally it is composed of 0.45% manganese, 0.030% max phosphorus, 0.030% max sulfur, 1.0% vanadium, 0.7% molybdenum, and 0.30% silicon. It is a popular knife steel due to its edge retention. Its major draw back is that when it becomes dull, it is harder to sharpen. Dues to its high chromium content it is often considered a semi-stainless steel

Dagger: A fighting knife that is designed for thrusting and stabbing.  Typically, daggers have spear point blades and are doulbe edged. As they are meant for thrusting, and edges are sharp, the dagger typically has a full corss guard. Compare to Pig Sticker, Bowie, Hunter, and Stiletto.

Damascus Steel:  Two or more types of steel of differing grades are heated and forge welded to create patterns in the blade.  The blades are then acid etched to further bring out the varying patterns of light and dark steels.  There is a myth that this somehow make the steel stronger and more resilient. In fact the steel is going to possess the weakest qualities of both steels. Damascus Steel is more correctly termed Pattern Welded Steel and almost always is made with carbon steel and is prone to rusting. Many high-end custom knife makers use Damascus steel because of the ability to fold a varsity "patterns" in the steel.

Two of the most commons steel used to make Damascus steel are 15N20 (also known as L6 or band saw steel) and 1095 Carbon steel. However, unless specified by the maker or seller, any two steels of differing properties can be used..

Deer Slayer:  A name sometimes applied to a large single bladed non-locking clasp knife.

Delrin:  A tough nylon based thermo plastic material  (Polyoxymethylene) that has many uses including the manufacturing of  knife handles. It is relatively easy to mould and is impact resistant making it a quality choice for composite handles, especially on work or utility knives. ( Delrin is often misspelled derlin. )

Desert Ironwood - DIW: A very hard, dense wood harvested from the Desert Ironwood Tree (Olneya Tesota) found only in the Sonora Desert located in the Southwestern United States and Northern Mexico.  DIW is regarded as some of the most beautiful wood anywhere.

Dining Knife /Dinner Knife / Table Knife : The term is interchangeable and refers to knives that are designed for use at the dinner table by the person dining. These include such knives and butter knives, butter spreaders, steak knives, etc. The hallmark is a critical aspect when it comes to collecting table /dining knives. In many cases the knife is seen as part of the entire dining set. See also Kitchen Knife and butter knife.

Doctor Knife: Traditionally, a relatively long straight handled knife with a long spear blade and a spatula blade. The pommel is often very flat and is used for crushing pills.

Today, many doctor’s knives have a long spear and short pen blade or just the single spear blade. This limits the value for the true collector. Some early Doctor Knives had a slender pin-like blade similar to a punch blade used for lancing boils but these are rare. Rare examples may also have a fleam or bloodletting blade. Also called a Physician's Knife, Pharmacist's Knife, or Pill Crusher

Dogleg:  A traditional handle pattern in which the handle is slightly crooked and resembles a dogs hind leg.  The top of the knife is narrower than the bottom. The top bolster is noticeably smaller than the butt end pommel. Both bolsters are normally rounded. The handle pattern is favored for Peanuts and Trappers.

Dots: Modern era Case knives use a dot numbering system to signify the year a knife was made. The dots normally appear as part of the knife's tang stamp. 10 dots signify a year ending in zero. With each passing year a dot is removed So for the decade beginning in 2000:

• 2000 =10 dots
• 2001= 9 dots
• 2002 =8 dots
• 2003= 7 dots
• 2004 = 6dots
• 2005= 5 dots
• 2006 =4 dots
• 2007= 3 dots
• 2008 =2 dots
• 2009= 1 dots

See the Case web site for more information on dating Case Knives < http://www.wrcase.com/index_en.php >

Double Action OTF: A knife with a retractable blade that deploys point first from the knife's handle. The blade is pushed forward manually using a release mechanism that follows a channel cut in the handle. The blade also manually retracted into the handle by pulling back on the release. The standard box cutter knife is an example of Double Action OTF. Also called a Slider. (see Gravity Knife and Single Action OTF for comparison.

Double-edged: The knife has both top and the bottom edges of the blade sharpened The blade cuts in either direction, with a strong sharp point. This shape is primarily used for fighting knives, daggers and stilettos.

Douk-douk: A simple knife originally made in France by Cognet. The knife was designed as in expensive knife for the French colonies and featured a simple warp around stamped stainless steel handle with a quality carbon steel blade. The knife was extremely popular in France's African Colonies and later became a favored weapon in colonial uprisings as they were easy to conceal. It was also easy to turn the folding knife into a crude fixed blade by hammering the metal hand together.

A modern Douk-Douk knife.

Drop Point: A blade on a knife where the top edge of the blade drops in a gentle concave arch toward the sharpened edge. Drop point blades are usually wide, short blades but not always The point rarely drops to the center line of the blade thus it is not a spear point.. They are useful for skinning.  Bob Loveless is credited with developing the design. Compare to coping and sheepfoot.

Drop Point

Duralumin: An age hardened aluminum/copper alloy sometimes used in knife pommels and cross guards. It is often used by Randall, Black Jack and other high priced custom knife makers.  The 4% copper content makes it any one of the several types 2024 Aluminum Alloys (AA2024).   It was originally used in rigid airship (Zeppelin) frames.  It remains popular in the aircraft and automobile industry because of its strength and durability. However, the high copper content makes it susceptible to corrosion.